For performance reasons, GitLab caches the HTML version of Markdown text
in fields like comments, issue descriptions, and merge request descriptions. These
cached versions can become outdated, such as
external_url configuration option is changed. Links
in the cached text would still refer to the old URL.
To avoid this problem, the administrator can invalidate the existing cache by
local_markdown_version setting in application settings. This can
be done by changing the application settings through
curl --request PUT --header "PRIVATE-TOKEN: <your_access_token>" "https://gitlab.example.com/api/v4/application/settings?local_markdown_version=<increased_number>"